Polymerization of erythrene and its homologues



Patented May 23, 1933 i.

I UNITED STATES PATENT, OFFICE 1 .7 CHEMICAL COMPANY, OF

NECTIC'UT annxannnn r. maxmorr, or vnncntnr, ITALY, ASSIGNOR To run nauca'rucx nauaa'rncx, comvncrrcur, a conronar'ron or 0011'- IPOLYHEBIZATION OF ERYTHRENE AND ITS HOMOLOGUES V I Drawing. Original application filedv Kay 8 1926, Serial No. 107,793. Divided and this application filed October 16, 1929. Serial No. 400,163.

This case is a division of my application Serial No. 107,793, filed May 8, 1926.

sions of erythrene or its homologues to give synthetic rubber latex. Another object is to carry out-such polymerization b means of fatty acids, fatty acid saltsor o substances containin such fatty acid compounds. A further 0 ject is to accelerate such 01ymerization in the presence of agents of the oxidizing type such as peroxides, bichromates, etc., terpenes, and the like. Another object is to prepare a synthetic rubber latex or water emulsion.

The following examples illustrate methods of carrying out the invention, but they are not intended to serve as limitations, .for other materials and proportions may be used. The'invention comprises emulsifying erythrene or a homologue thereof in water with a fatty acid compound and polymerizing this emulsion in the presence of a peroxide, removing unpolymerized erythrene and recovering an aqueous emulsion of synthetic rubber, that is a synthetic rubber latex. The invention also includes the production of latices containing synthetic rubber as well as natural rubber.-

One method of carrying out the invention is as follows: 100 parts of dimethyl-erythrene and 8.7 parts by weight of oleic acid.

a are emulsified in 360 parts by volume of 10% ammonium hydroxide. To this emulsion are then'added 18 parts b .volume of a 3% hydrogen peroxide. T e emulsion then allowed to stand at room temperature for about 8 days. Unpolymerized dimethyl erythrene may be removed by heating theemulsion to the boiling point of dimethyl-erythrene. The remaining emul sion comprises a synthetic rubber latex, in that it is a latex containing synthetic rub- V. ,Qber in emulsified form. It may be coagu- 80' lated'by'the' addition of acetic'acidor most of the other known coagulants for ordinary rubber latex. The proportion of peroxide may be increased whereupon the amount of polymer will be increased, and the the same time may have somewhat different properties,

' particularly in its increased adhe'siveness.

drogen peroxide, other oxidizing agents may be employed. Potassium bichromate may be used and other well known oxidizing agents. i In the above example the oleic acid and ammonia form ammonium oleate, and 'in some instances'it may be desirable to add ammonium oleate as such instead of forming this compound in the emulsion. Other bases may be used instead of ammonium hydroxide, although the latter is preferred. Saponin may be employed in the formation of the emulsion. In the above exampleammonium oleate acts as a polymerization agent, while the peroxide functions as an accelerator of such polymerization. This be ing the case the peroxide may be omitted if desired. As an illustration, 100 grams of dimethyl e'rythrene .may be emulsified with 3.6 grams of oleic acid and .120 cos. of 10% ammonium hydroxide. lThis emulsion will give a synthetic rubber-latex containing about of rubberafter five days standthe amount of polymer formed in the same time.

An acceleration of polymerization is also exhibited by other fatty acids, such as stearic acid. The use of -ox1dized linseed oil for example as a source of fatty acid likewise furnishes an increased yield of rubber. In five days at room temperature an emulsion containing dimethyl erythrene, oleic acid, ammonia and oxidized linseed oil yielded about 80% of rubber. The property of acting as polymerization agents is exhibited by oxidized fatty acids, as well as by am.- monium salts and ethers of the unsaturated aliphatic acids.

Dimers of the terpene series function as accelerators of polymerization. sion is made of 100 grams of dimethyl erythrene, grams of oleic acid, 350 cc. of 10% ammonium hydroxide, 70 cc. of 3% hydrogen peroxide and 1 cc. of turpentine. This emulsion, after standing for 5 days at room temperature will give approximately 65% of rubber.

Similar results may be obtained with erythrene instead of dimethyl erythrene, but since er hrene is a gas at ordinary temperatures, t e polymerization must be carried out under pressure, for exam le in an autoclave at 2-3 atmospheres. 'T e unpolymerized erythrene will evaporate olf when the pressure is released.

To produce a latex of synthetic rubber,

substantially similar to natural latex, one may add to the emulsion suitable proteins, resins and inorganic material. The synthetic rubber latex may be blended with natural latex. The above invention furnishes a method for preparing the so-called artificial latices. Ordinary rubber, such as crepe, ma be softened with dimethyl erythrene an then emulsified in water contamirfiga polymerizing agent such as ammonium oleate, and if desired, an accelerator of polymerization. This emulsion, wherein 'the rubber and'the erythrene arediscontinuous phases, when'allowed to stand for a fewdays at room temperature, will comprise an artificial latex containing synthetic rubber. If erythrene be used in' placggi of dimethyl erythrene the .einu'lsification and polymerization may be carried out under pressure. Either vulcanized or reclaimed rubber may be usedinstead of crude rubber. In place of erythrene, its homologues, such as isopren'e, piperylene, phenyl-butadiene, and also may, be,employed'. The homologues of erythrene include acyl aryl and heterocyclic substitutions.

rubber latex may be obtained. It is possible by this means to obtaina latex which will An emuland-synthetic rubber form dispersed ispe By changin the proportions of catalyst 'eld a very sticliy rubber, suitable for adeslve purposes.-

If'it' be desired to recover rubber from these synthetic latices, it is only necessary to add a latex coagulant, for example acetic acid, and the rubber is coagulated and may be recovered in the usual wa The synthetic rubber may be recovere if desired, by evaporation of the latex, or by spraying, or by. other methods.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

1. A method for preparin a rubber dispersion which -comprises so ning rubber with a rubber-forming hydrocarbon, emulsifying the softened rubber, and polymerizing the rubber-forming hydrocarbon in the emulsion. 4

2. A. method for preparing a rubber dis-" persion which comprises softening rubber with anerythrene, emulsifying the softened rubber in water containing an emulsifying agent, and polymerizing the erythrene in the emulsion. U

3. As a new product, an aqueous dispersion containing both natural rubber and s thetic rubber as discontinuous-phases in t e aqueous medium thereof, said synthetic rubber being a polymerization product of a1 diene hydrocarbon.

4. As a. new product, an aqueous dispersion containing both natural rubber and a butadierfe rubber as discontinuous phases.

5. As a new roduct, an aqueous dis r-. sion containing th natural rubber an dimlpthyl erythrene rubber as discontinuous ases.

p 6. As a new product, an aqueousdispersion containing both natural rubber and-106 mono-methyl-erythrene rubber as discontinuous hases. I

7. method of preparing a rubber dispersion which comprises softening rubber with a rubber-formi hydrocarbon, emulsi 'ng' sa'id softened ru ber in an aqueous me ium containing a polymerizing agent and an accelerator of the pol erization, and'then polymerizing the rub r emulsion.

8. As a new product an artificially re'-.' pared latex in which both natural ru r bases the rse or continuous phase siereof comprislngwater' and a soa said synthetic rubber being a polymerization product of a diene hydrocarbon. r

Signed at Milan, Italy, this 27th day of September 1929.

'' ALEXANDER 'r. MAXIMOFE r V 1 12s 

